Individual rights - Substantive due process

Learning Outcomes

This article explains Substantive Due Process under the Fifth and Fourteenth Amendments, including:

• Distinguishing substantive due process from procedural due process and equal protection, and selecting the correct doctrinal framework on timed MBE questions.
• Identifying when a fundamental right is implicated, spotting fact patterns that hide the right being burdened, and choosing the correct standard of review.
• Applying strict scrutiny versus rational basis, knowing who bears the burden, and articulating clear, exam-ready rule statements for each level of scrutiny.
• Understanding how privacy, family, sexual intimacy, interstate travel, voting, and other autonomy interests are treated as fundamental rights, and recognizing when intermediate scrutiny is inapplicable.
• Evaluating economic and social legislation, retroactive laws, and other non-fundamental interests under rational basis review, including when a law fails for being arbitrary or motivated by impermissible animus.
• Analyzing historic and current abortion doctrine, contrasting the pre-Dobbs undue burden test with the modern rational-basis approach, and applying whichever framework the question instructs you to use.
• Translating doctrinal rules into step-by-step issue-spotting sequences so you can quickly identify the right, state the test, allocate burdens, and reach a defensible conclusion on multiple-choice and essay questions.

MBE Syllabus

For the MBE, you are required to understand substantive due process, with a focus on the following syllabus points:

• Identifying the sources of Substantive Due Process (Fifth and Fourteenth Amendment Due Process Clauses).
• Distinguishing Substantive Due Process from Procedural Due Process and Equal Protection.
• Recognizing fundamental rights (e.g., privacy, interstate travel, voting) versus non-fundamental rights.
• Applying strict scrutiny to laws burdening fundamental rights.
• Applying rational basis review to laws affecting non-fundamental rights, especially economic and social legislation.
• Understanding past and current constitutional standards for abortion regulations and how exam questions may frame them.
• Evaluating retroactive legislation under substantive due process.
• Analyzing economic regulation and other non-fundamental interests under rational basis review.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Which constitutional standard is typically applied when a state law significantly burdens a fundamental right protected by Substantive Due Process?
   1. Rational basis test
   2. Intermediate scrutiny
   3. Strict scrutiny
   4. Undue burden test
2. A state enacts a law prohibiting the sale of widgets on Tuesdays for purely economic reasons, aiming to boost Wednesday sales. A widget seller challenges the law under the Fourteenth Amendment's Due Process Clause. Which standard of review will the court most likely apply?
   1. Strict scrutiny, because the law interferes with the right to contract.
   2. Rational basis, because economic regulation generally involves non-fundamental rights.
   3. Intermediate scrutiny, because the law affects commercial activity.
   4. Undue burden test, because the law impacts the seller's business operations.
3. Which of the following rights is LEAST likely to be considered a fundamental right triggering strict scrutiny under Substantive Due Process?
   1. The right to marry
   2. The right to engage in interstate travel
   3. The right to government-funded healthcare
   4. The right to use contraception

Introduction

While Procedural Due Process ensures fair procedures when the government deprives someone of life, liberty, or property, Substantive Due Process (SDP) limits the substance of laws and governmental regulations. It asks whether the government has an adequate reason for taking away a person’s life, liberty, or property. The focus is on what the government is doing, not how it does it.

Key Term: Substantive Due Process
A constitutional principle, under the Fifth and Fourteenth Amendments, that prevents the government from enforcing laws that are arbitrary, irrational, or that infringe upon certain fundamental rights, regardless of the fairness of the procedures used.

The Due Process Clause of the Fifth Amendment applies to the federal government; the Due Process Clause of the Fourteenth Amendment applies to state and local governments. The same substantive standards are used under both.

The core of SDP analysis is:

• What right or interest is affected?
• How important is that right (fundamental vs non-fundamental)?
• How closely must the law be tailored to the government’s objective (which standard of review applies)?
• Who has the burden of proof—government or challenger?

Substantive Due Process vs Procedural Due Process vs Equal Protection

On the MBE, you must quickly distinguish these three:

• Procedural Due Process: Is the government using fair procedures (notice and hearing) before depriving a specific person of life, liberty, or property?
• Substantive Due Process: Is the government’s rule itself (the statute, regulation, or policy) unreasonable or overreaching as to everyone it covers?
• Equal Protection: Is the government treating some people differently from others (a classification), and is that differential treatment justified?

A quick exam heuristic:

• A law that forbids all people from doing X → likely Substantive Due Process.
• A law that forbids only some group (e.g., unmarried persons, nonresidents) from doing X → likely Equal Protection (though the same fundamental-right analysis and level of scrutiny often apply).

Key Term: Police Power
The general authority of state and local governments to legislate for the health, safety, welfare, and morals of their citizens. Most substantive due process cases ask whether a law passed under the police power is sufficiently justified.

For example, a universal motorcycle-helmet requirement is an exercise of the state’s police power. SDP asks whether that exercise is rational (for non-fundamental interests) or is narrowly tailored to a compelling interest (if it burdens a fundamental right).

How to Approach a Substantive Due Process Question on the MBE

A systematic approach is essential:

1. Identify the actor: Federal (Fifth Amendment) or state/local (Fourteenth Amendment).
2. Ask: law or procedure?
   • Complaint about lack of hearing, no notice, or biased decisionmaker → Procedural DP.
   • Complaint that the law itself is too broad, irrational, or burdens a liberty interest → Substantive DP (or sometimes Equal Protection).
3. Determine whether a classification is involved:
   • If the law targets a group (e.g., nonresidents, unmarried people), consider Equal Protection.
   • If it applies to everyone, think Substantive DP.
4. Identify the right being affected:
   • Is it a fundamental right (e.g., marriage, contraception, childrearing, interstate travel, voting, core First Amendment rights)?
   • Or a non-fundamental interest (e.g., running a business, choosing a profession, economic regulation)?
5. Select the standard of review:
   • Fundamental right → strict scrutiny.
   • Non-fundamental right → rational basis.
6. Allocate the burden:
   • Strict scrutiny → government must justify the law.
   • Rational basis → challenger must show the law is irrational.
7. Apply the standard to the facts.

The rest of this article develops the standards and the key rights you will see on the MBE.

Standards of Review

The level of justification the government must show depends entirely on whether the law affects a fundamental right or a non-fundamental right.

Key Term: Fundamental Rights
Rights deemed deeply rooted in the nation’s history and tradition or implicit in the concept of ordered liberty. They include core privacy and autonomy rights (marriage, procreation, contraception, family relations), interstate travel, voting, and most First Amendment rights.

Key Term: Strict Scrutiny
The most demanding standard of judicial review. The government must prove that the challenged law is necessary (narrowly tailored, using the least restrictive means) to achieve a compelling governmental interest.

Key Term: Intermediate Scrutiny
A standard of review under which the government must show that a law is substantially related to an important governmental interest. In modern doctrine it is used primarily in Equal Protection cases (gender and legitimacy), and almost never in pure substantive due process analysis.

Key Term: Rational Basis Test
The most deferential standard of review. The challenger must prove that the law is not rationally related to any legitimate governmental interest. Courts will uphold the law if any conceivable legitimate purpose could justify it.

Fundamental Rights: Strict Scrutiny

If a law limits a fundamental right, it will be upheld only if the government can prove that the law is necessary to achieve a compelling governmental purpose—strict scrutiny.

Under strict scrutiny:

• The government bears the burden of proof.
• The interest must be compelling, not merely important or legitimate.
• The law must be narrowly tailored—it should use the least restrictive means. If a less intrusive way exists to achieve the same goal, the law fails.
• Overinclusive or underinclusive laws are suspect because they suggest the legislature did not narrowly tailor the means to the ends.

In practice, very few laws survive strict scrutiny.

Examples where strict scrutiny applies in SDP:

• State prohibition on interracial marriage or same-sex marriage.
• Statute requiring state approval before parents can send children to private schools (interferes with parental and educational choices).
• Durational residency requirement that delays access to basic welfare benefits for a year (burdens interstate travel).
• Severe restrictions on voting rights beyond age, citizenship, and residency.

Non-Fundamental Rights: Rational Basis Test

If a law does not affect a fundamental right (e.g., most economic regulations, business regulations, land use, taxation, and social welfare laws), the law is reviewed under the rational basis test.

Under rational basis:

• The challenger bears the burden of proof.
• The government’s objective need only be legitimate (e.g., public safety, public health, economic regulation).
• The means chosen need only be rationally related to that interest; the law need not be particularly wise, effective, or fair.
• The legislature may address problems one step at a time and may be overinclusive or underinclusive without failing the test.

Courts are extremely deferential here; most laws survive rational basis review. Only laws based on pure animus or that are wholly irrational tend to be struck down.

Key Term: Economic Rights
Interests in pursuing common occupations, engaging in business, and making contracts. These are not fundamental rights for substantive due process; regulations affecting them are reviewed under the rational basis test.

Classic rational-basis areas:

• Licensing requirements for professions (doctors, lawyers, sonographers).
• Zoning and land-use restrictions (excluding certain businesses from residential zones).
• Wage and hour laws, price controls, rent regulations.
• Most social welfare programs (e.g., allocation of benefits).

Worked Example 1.1

State Green enacts a law requiring all persons operating a motor vehicle to wear a seatbelt. A driver challenges the law, claiming it infringes upon his liberty interest to decide what safety measures to take for himself, violating Substantive Due Process. What standard of review applies?

Answer:
Rational basis. The choice not to wear a seatbelt is not a fundamental right. The law is an exercise of the state’s police power aimed at promoting public safety and reducing injuries—a legitimate government interest. Requiring seatbelts is rationally related to that interest. The challenger bears the burden and will almost certainly lose.

Worked Example 1.2

A state law requires all individuals seeking a license to practice medicine within the state to pass a rigorous exam demonstrating competence. Dr. Able, who failed the exam, challenges the law, arguing it arbitrarily deprives him of his liberty to practice his chosen profession. Will Dr. Able likely succeed?

Answer:
No. The right to practice a profession is an economic right, not a fundamental right. Ensuring competence among doctors furthers the legitimate interest of protecting public health. Requiring an exam is rationally related to that interest. Under the rational basis test, Dr. Able must show the law is irrational, which he cannot do. The law will be upheld.

Worked Example 1.3

In response to a highly publicized incident involving a sonographer who misread a scan, a state lengthens the education required for a sonographer’s license from one year to two years. A clerk already enrolled in a one‑year program sues, claiming it is unconstitutional to apply the new two-year requirement to him.

Answer:
The state will prevail. The right to become employed as a sonographer is an economic right, subject to rational basis review. The legislature could rationally believe that additional training improves patient safety. The law need not include a grandfather clause for current students to be rational. There is no fundamental right at stake, so strict scrutiny does not apply.

Identifying Fundamental Rights

Determining whether a right is fundamental is essential for SDP analysis. The Supreme Court generally asks whether the claimed right is:

• Deeply rooted in the nation’s history and tradition, and
• Implicit in the concept of ordered liberty such that neither liberty nor justice would exist if it were sacrificed.

Many fundamental rights cluster around privacy and personal autonomy.

Key Term: Right to Privacy
A group of related fundamental rights protecting intimate and personal decisions, including marriage, procreation, contraception, parental control of children, family living arrangements, and certain sexual decisions among consenting adults.

Privacy-Related Rights

Key privacy-related rights include:

• Marriage:
  The right to marry is fundamental. Laws that substantially interfere with the ability to marry—whether by prohibiting interracial marriage or same-sex marriage—are invalid. Reasonable regulations (age limits, licensing fees, brief waiting periods) that do not significantly burden the right are generally upheld.

• Procreation:
  The right to decide whether to have children is fundamental. Laws imposing mandatory sterilization of certain groups, absent compelling justification and narrow tailoring, are unconstitutional.

• Contraception:
  Adults, whether married or unmarried, have a fundamental right to purchase and use contraception. A blanket ban on contraceptives, or on their sale to unmarried persons, fails strict scrutiny.

• Family Relations and Childrearing:
  Related family members (e.g., grandparents, cousins) have a fundamental right to live together, and parents have a fundamental right to direct their children’s upbringing and education.

  This includes:

  • Choosing private or religious schools.
  • Making decisions about discipline and religious training.
  • Control over visitation and custody, subject to child-protection laws.

• Sexual Intimacy:
  The Court has held that the government has no legitimate interest in criminalizing private, consensual, adult, non-commercial sexual intimacy, including same-sex intimacy. While not always labeled a “fundamental right,” laws targeting such conduct have been invalidated even under a “rational basis” analysis because they are based solely on moral disapproval.

Abortion and the Undue Burden Test (Past and Present)

Historically, under Roe v. Wade and Planned Parenthood v. Casey, the Court treated the decision to terminate a pregnancy before fetal viability as protected under substantive due process and applied the undue burden test:

Key Term: Undue Burden Test
Under pre‑2022 Supreme Court precedent, a law regulating pre‑viability abortion was invalid if its purpose or effect was to place a substantial obstacle in the path of a woman seeking an abortion.

Under that earlier framework:

• Before viability:
  The state could regulate abortion (e.g., informed consent, 24‑hour waiting periods, parental consent with judicial bypass) so long as it did not impose an undue burden.
• After viability:
  The state could prohibit abortion except where necessary to protect the life or health of the pregnant person.

Examples historically not found to be undue burdens:

• Informed consent requirements.
• Short waiting periods (e.g., 24 hours).
• Parental consent or notification for minors, if a genuine judicial bypass procedure existed.

Examples historically found to be undue burdens:

• Spousal notification requirements.
• Regulations that effectively closed most clinics in a state without clear health justification.

Current law after Dobbs v. Jackson Women’s Health Organization (2022).
The Supreme Court has now held that the federal Constitution does not protect a right to abortion as a fundamental right, and it explicitly rejected the undue burden framework. State abortion regulations are now generally reviewed under rational basis (unless some other constitutional right is implicated).

For MBE purposes:

• If a question expressly tells you to apply Casey’s undue burden framework or describes pre‑Dobbs doctrine, apply the undue burden test as described above.
• If the question is framed in terms of current constitutional law without such instructions, you should assume that abortion regulations are not subject to strict scrutiny or the undue burden test and are typically upheld if rationally related to a legitimate state interest (e.g., protecting potential life or maternal health).

Other Fundamental Rights

Right to Interstate Travel

Key Term: Right to Interstate Travel
A fundamental right to move freely between states, enter and leave states, and be treated equally as a new permanent resident of a state.

The right to travel has several components:

• Freedom to move between states.
• Freedom to be welcomed as a permanent resident on equal terms with longer-term residents for basic rights and important benefits.
• A somewhat lesser-protected interest in international travel.

Laws that penalize people for newly entering a state or that condition essential benefits on a long residency period can trigger strict scrutiny.

Examples:

• A one-year residency requirement for welfare benefits or medical care → usually invalid (strict scrutiny).
• A residency requirement before voting in a state → allowed only if brief and necessary to ensure bona fide residence.
• Higher in‑state/out‑of‑state tuition for state universities → generally valid as a rational basis distinction, because education is not a fundamental right and benefits here are not considered essential in the same way as subsistence welfare.

Right to Vote

Key Term: Right to Vote
A fundamental right of citizens to participate in elections on an equal basis. Severe burdens on the right to vote trigger strict scrutiny.

Although voting cases are often analyzed under Equal Protection, the right to vote is also treated as a fundamental liberty interest. Scrutiny depends on how severe the burden is:

• Poll taxes or property qualifications → unconstitutional.
• Gross malapportionment of voting districts → violates “one person, one vote” principle.
• Reasonable, nondiscriminatory regulations (e.g., neutral voter ID rules, basic registration deadlines) usually survive more flexible review.

For MBE purposes, substantial restrictions on access to the ballot or arbitrary differences in voting power are almost always unconstitutional.

Worked Example 1.4

A state requires new residents to live in the state for one year before they are eligible for state-funded basic medical care for indigent persons. A person who moved to the state six months ago and needs urgent surgery challenges the law.

Answer:
Strict scrutiny applies because the durational residency requirement burdens the right to interstate travel and access to essential benefits. The state could pursue cost control in less restrictive ways (e.g., income tests) without discriminating against new residents. The law is unlikely to be found necessary to achieve a compelling interest and will probably be struck down.

Non-Fundamental Rights and Rational Basis Review

Non-Fundamental Rights Examples

Many interests are not fundamental for substantive due process purposes. Regulation of these is judged under the rational basis test.

Key non-fundamental areas:

• Economic Rights:
  • Freedom of contract and business operation.
  • Right to practice a trade or profession (subject to reasonable licensing and competency requirements).
• Education:
  There is no fundamental right to public education. States may structure and finance schools as they choose, subject mainly to Equal Protection constraints (e.g., no racial segregation).
• Social and economic benefits:
  There is no fundamental right to government-funded healthcare, welfare, or public housing themselves, although once granted, procedural due process protections may attach to continued receipt.
• Government employment:
  No fundamental right to a government job. Regulation of hiring and firing is subject to rational basis unless it burdens another fundamental right (e.g., speech, association).
• Physician-Assisted Suicide:
  Not recognized as a fundamental right. States may prohibit or allow physician-assisted suicide under rational basis review.
• Lifestyle regulation:
  Laws requiring motorcyclists to wear helmets, limiting smoking in public places, or imposing safety regulations are evaluated under rational basis.

Even under rational basis, some laws can fail if they are irrational or rest purely on illegitimate animus toward a group. But these are rare.

Retroactive Legislation and Substantive Due Process

Substantive due process also constrains retroactive legislation—laws that change legal consequences after the fact—when other specific clauses (Ex Post Facto, Contracts Clause, Bills of Attainder) do not apply.

Key Term: Retroactive Legislation
Law that changes the legal consequences of actions after they have occurred. If no other specific constitutional provision applies, such laws are evaluated under substantive due process.

Key points:

• If no fundamental right is affected, retroactive laws are upheld if they are rationally related to a legitimate government purpose.
• Retroactive tax laws are often upheld under rational basis if they serve legitimate fiscal goals and are not grossly unfair.
• Retroactive changes that merely alter remedies (e.g., extending a statute of limitations) are usually valid unless they completely extinguish vested property rights without justification.

Worked Example 1.5

A state enacts a law retroactively shortening the limitations period for filing property damage claims from three years to one year, immediately barring a plaintiff’s pending claim filed after two years. The plaintiff challenges the law under the Due Process Clause.

Answer:
No fundamental right is involved; access to this particular cause of action is not itself a fundamental right. The question is whether the retroactive law is rationally related to a legitimate state interest (e.g., preventing stale claims, limiting litigation costs). Because the law is harsh but not irrational, it will likely be upheld under rational basis review. Only when retroactive laws are arbitrary or wipe out vested rights without any legitimate justification will they fail substantive due process.

Key Point Checklist

This article has covered the following key knowledge points:

• Substantive Due Process derives from the Fifth and Fourteenth Amendments and limits the substance of government action affecting life, liberty, or property.
• The first step is to distinguish Substantive Due Process from Procedural Due Process (procedures) and Equal Protection (classifications).
• Analysis turns on whether a fundamental or non-fundamental right is implicated.
• Fundamental rights include core privacy rights (marriage, procreation, contraception, family relations), interstate travel, voting, and most First Amendment rights.
• Laws that significantly burden fundamental rights are reviewed under strict scrutiny: the government must prove the law is necessary (narrowly tailored, least restrictive means) to achieve a compelling interest.
• Laws affecting non-fundamental rights, including most economic and social regulations, are reviewed under the rational basis test: the challenger must show the law is not rationally related to any legitimate government interest.
• Intermediate scrutiny is generally an Equal Protection concept and is rarely used for pure substantive due process claims.
• Privacy-related sexual intimacy between consenting adults is strongly protected; laws targeting such conduct typically fail even rational basis because the government lacks a legitimate interest in regulating it.
• Historically, pre‑viability abortion regulations were reviewed under the undue burden test; after Dobbs, the federal Constitution no longer recognizes a fundamental right to abortion, and abortion regulations are generally reviewed under rational basis unless the question explicitly invokes pre‑Dobbs doctrine.
• The right to interstate travel and serious burdens on the right to vote trigger strict scrutiny and are frequently tested on the MBE.
• Retroactive legislation that does not affect a fundamental right is generally upheld if it satisfies rational basis review.

Key Terms and Concepts

• Substantive Due Process
• Police Power
• Fundamental Rights
• Right to Privacy
• Right to Interstate Travel
• Right to Vote
• Strict Scrutiny
• Intermediate Scrutiny
• Rational Basis Test
• Undue Burden Test
• Retroactive Legislation
• Economic Rights